Flow through nebulizer

ABSTRACT

A nebulizer having a bottom cup for storing liquid medication. The bottom cup has an opening therethrough to receive a source of pressurized air. A housing includes an open bottom removably attachable to the bottom cup, an open top outlet, walls extending therebetween, and an air inlet tube extending through one of the walls, traversing the housing, and terminating in an aperture adjacent the open bottom so that air entering the inlet tube will pass through and across the housing before entering the housing adjacent the open bottom. A cover is receivable within the bottom cup so that liquid medication can be drawn from the bottom cup by induction and form droplets, whereby the pressurized air and the liquid droplets will impinge on the air inlet tube of the housing, thereby breaking into micron-size droplets.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a breathing device for administering aliquid medicant to a patient. In particular, the present invention isdirected to a breathing device that is simple in design, easy tomanufacture, and is comprised of a relatively small number ofcomponents.

2. Prior Art

The use of nebulizers or atomizers with intermittent positive pressurebreathing (IPPB) equipment, ventilators, or with the patient's ownnatural breathing effort is widely practiced. Nebulizers or atomizersare used to deliver liquid medicants for a wide variety of medicalconditions.

There is increasing concern over treatment of contagious diseases, theconcern being both for infection of other patients and for infection ofmedical personnel. For this reason, the use of disposable nebulizerswhich are discarded after a single patient's use has become popular.While many nebulizers are produced so that they may be washed andsterilized, and then reused, there is a demand for disposablenebulizers.

Although existing nebulizers may be discarded after each use, it iscostly to discard the more expensive, complicated nebulizers.

Disposable nebulizers produced in the past have not been as effective asthe reusable nebulizers. As an example, the Applicant's invention shownin U.S. Pat. No. 4,007,238 includes a feature not common to disposablenebulizers. The performance of the nebulizer is directly responsive tothe patient's own breathing. Stated another way, the output ofmedication matches the patient's changing rate of inhalation. All of theair inhaled by the patient is directed past the saturated mist. As theair flow to the patient's lungs is increased, additional liquidparticles are delivered to the lungs because these particles aresurrounded by a shroud of high relative humidity. Conversely, when theair flow to the patient's lungs is decreased, the number of liquidparticles is decreased. The amount of saturated air delivered to thepatient is directly responsive to the increase or decrease in thepatient's breathing.

Additionally, an extremely small average particle size is called for indelivery of liquid medication. For the liquid medication to reach thesmaller passages in the bronchial tubes and lungs, the size of theliquid particles must be below five microns. These small particles arebelow the visible range.

Furthermore, the actual particle count delivered is of great importance.

It is desirable to incorporate these features in a nebulizer which issimple in design and is directed to the disposable market.

Accordingly, it is a principal object and purpose of the presentinvention to provide a nebulizer which is simple in construction, whichis easy to produce, and which may be fabricated from a minimum number ofcomponents.

It is an additional object and purpose of the present invention toprovide a disposable nebulizer having a medication delivery system thatis responsive to the patient's breathing.

SUMMARY OF THE INVENTION

The nebulizer of the present invention includes a housing having acylindrical chimney. At one end of the housing is an open bottom and atthe opposite end, an open top outlet.

An atmospheric air inlet tube has a first end open. The air inlet tubeextends through the cylindrical chimney and extends through and acrossthe housing about the diameter of the chimney.

From its entry point, the air inlet tube extends to the opposite side ofthe chimney where a downward opening is provided. Ambient air enteringthe intake tube will, thus, travel through and across the housing andexit from the inlet tube toward the open bottom.

A bottom medication cup is removably attached to and encloses the openbottom of the housing. The bottom cup has a conical portion extendingfrom a base. At the concentric top of the conical portion is an orifice.Extending from the conical portion, in communication with the orifice,is a nozzle holder which would be connected to a source of pressurizedair.

Received within the bottom medication cup is a cover which nests on topof the conical portion of the bottom cup. The cover has an opening whichis aligned with the orifice of the bottom cup.

A protruding target extends radially outward from the air intake tube.The protruding target extends outward toward the open bottom and towardthe conical portion of the bottom cup. The protruding target ispositioned so that it is above and spaced from the opening.

During operation of the nebulizer, a stream of pressurized air will flowthrough the orifice of the bottom cup causing induction of the liquidmedication from the bottom cup through a space between the cup and theconical portion. Accordingly, liquid droplets of medication will bemoved at high velocity into the housing.

The protruding target, thus, provides a target against which liquiddroplets and pressurized air will move at high velocity. A stream ofpressurized air and liquid droplets exiting from the opening will, thus,be caused to impinge against the target as well as against the airintake tube.

A pair of opposed, accurate skirts extend radially outward from the airintake tube and surround the protruding target.

Near the open bottom, the housing has an enlarged chamber axiallyaligned with the chimney, the housing having a larger diameter than thechimney. Air entering the air intake tube will pass across and throughthe housing within the intake tube, and will enter the enlarged chamber.Thereafter, the air will enter the chimney and pass around thehorizontal air intake tube, mixing with the liquid droplets, vapor andpressurized air. Finally, the flow will-be directed upward through theinterior of the chimney.

A longitudinal chamber extends adjacent the chimney in communicationwith the air intake tube. If the nebulizer is tipped from the uprightposition, the liquid medication will flow into the longitudinal chamberor the enlarged chamber. Thus, the liquid medication will not spill outof the open top or out of the air intake tube if the nebulizer is tippedfrom its upright position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a nebulizer constructed in accordance withthe present invention;

FIG. 2 is a sectional view of an alternate embodiment of the presentinvention;

FIG. 3 is a top view of the nebulizer shown in FIG. 1; and

FIG. 4 is a side view of the nebulizer shown in FIG. 1.

FIG. 5 is a sectional view of a nebulizer constructed in accordance withthe present invention and disclosing a check-valve adjacent the open topoutlet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in detail, FIG. 1 illustrates a sectional viewof a nebulizer 10 constructed in accordance with the present invention.

The nebulizer 10 includes a housing 14 which is normally positionedupright when in use. In the present embodiment, the housing 14 hassubstantially cylindrical walls to form a cylindrical chimney 16. At oneend of the housing is an open bottom 18 and, at the opposite end, anopen top outlet 20. It will be understood that although the chimney 16is substantially cylindrical in the present embodiment, other shapesmight also be utilized.

An atmospheric air inlet tube 22 has a first end 23 open. The air inlettube 22 extends through the wall of the chimney 16 and extends throughand across the housing 14, traversing the diameter of the chimney.

From its entry point, the air inlet tube extends to the opposite side ofthe chimney 16 where a downward opening 24 is provided. In the presentembodiment, the air inlet tube is cylindrical in form and issubstantially perpendicular to the cylindrical chimney 16 of the housing14. Ambient air entering the air intake tube 22 will, thus, travelthrough and across the housing and exit from the tube 22 toward the openbottom 18 as shown by arrows 26.

A bottom medication cup 28 is removably attached to and encloses theopen bottom 18 of the housing 14. In the embodiment shown, the openbottom 18 is internally threaded and the medication cup 28 is externallythreaded. Other methods of attachment are, of course, possible. When thebottom cup 28 is attached, a closed chamber is formed, with theexception of the open end 23 of the air intake tube and the open top 20.

In the present embodiment, the bottom cup 28 has substantiallycylindrical outer walls 30. The bottom cup 28 has a conical portion 32extending from base 33 that is concentric with the walls 30. At theconcentric top of the conical portion is an orifice 34. Extending fromthe conical portion and in communication with the orifice 34 is a nozzleholder 36. The nozzle holder 36 would be connected to a source ofpressurized air (not shown) so that pressurized air would be deliveredinto the nebulizer.

Received within the bottom medication cup 28 is a cover 40 which nestson top of the conical portion 32 of the bottom cup 28. The cover 40 hasan opening 42 which is aligned with the orifice 34 of the bottom cup.

During operation of the nebulizer 10, a stream of pressurized airindicated by arrow 44 will flow through the orifice 34 of the bottom cupand cause induction of the liquid medication 46 (illustrated by dashedlines) from the bottom cup through a space between the cover 40 and theconical portion 32. Accordingly, liquid droplets of medication will bemoved at high velocity through the orifice and into the housing.

It will be recognized that other mechanisms to induct the liquidmedication, such as a capillary tube, might alternatively be utilized.

Returning to a consideration of the housing 14, a protruding target 48extends radially outward from the air intake tube 22. The protrudingtarget 48 extends outward toward the open bottom 18 and the conicalportion 32 of the bottom cup. The protruding target 48 is positioned sothat it is above and spaced from the opening 42.

The protruding target 48, thus, provides a target against which liquiddroplets and pressurized air will move at high velocity. The stream ofpressurized air and liquid droplets exiting from the opening 42 will,thus, be caused to impinge against the target 48 and against the airintake tube 22. It will thus be observed that the air inlet tube itselfserves as a baffling mechanism for the liquid particles.

A pair of opposed, accurate skirts 50 and 52 extend radially outwardfrom the air intake tube 22 and surround the protruding target 48. Theend of the skirts may touch and rest against the cover 40. Largedroplets that remain after striking the target 48 and air intake tubewill fall by gravity back into the medication cup. The liquid medicationmay then pass once again through the described system.

Near the open bottom 18, the housing has an enlarged chamber 54 axiallyaligned with the chimney and having a larger diameter than the chimney.Ambient air entering the air intake tube 22 will traverse the housingwithin the intake tube, and will enter the enlarged chamber 54. The airwill then change direction and enter the chimney 16 as indicated byarrows 58. The air will pass around the horizontal air intake tube 22and mix with the liquid droplets and pressurized air. The fine mistproduced by the liquid droplets and pressurized air impinging on thetarget is mixed and swept along with the atmospheric air. The air flowwill be directed upward through the interior of the chimney.

Finally, the saturated mist will exit the nebulizer 10 to be inhaled bythe patient (not shown) from the top outlet 20 as indicated by the arrow64.

Returning to a consideration of the air intake tube 22, a longitudinalchamber 60 extends adjacent the chimney 16. The chamber extends radiallyfrom and is in communication with the air intake tube. If the nebulizer10 is accidentally tipped from the upright position, the liquidmedication will flow into the chamber 60 if tipped in one direction orthe enlarged chamber 54 if tipped in the opposite direction.

It will be observed that the entire nebulizer may be constructed ofthree component parts. The housing 14, including the air intake tube 22and target 48 may be constructed of a single piece. The bottommedication cup 28 and the cover 40 comprise the only other components.

If a patient wishes to use a metered dose inhaler (MDI), the MDI can beadded to the ambient air inlet tube 22 of the nebulizer 10. This permitsthe baffling system of the present invention to filter out the largerdroplets of medication from the MDI. Use of the present invention with ametered dose inhaler will help overcome a systemic side effect of MDI'swhich is the ingestion of larger particles into the patient's stomach.

Distilled water might be placed in the medication cup while a MDI isbeing used. Flow from an air compressor or other pressurized air sourcegenerates a high relative humidity aerosol which blends with themedication.

Large droplets of medication would be filtered out an collected in themedication cup along with the distilled water. They would then bere-nebulized for delivery to the patient.

As seen in FIG. an additional check or flapper valve might be added tothe nebulizer to further reduce the average particle size. The removablebaffle mechanism might be inserted into the open top 20 of the housing.One type of check valve might be comprised of a flexible membrane whichacts as a one way valve to allow the mist to exit from the chimney. Asthe patient inhales, the valve membrane would lift to allow the mist topass from the chimney. The use of the valve membrane will also act as asecondary baffling system and restrict some of the larger particles frompassing out of the open top.

By placing this additional mechanism in the chimney, large droplets willbe knocked out and will descend, returning to the medication cup.

The present invention also is readily adaptable to presently existingfiltration systems to prevent distribution of medication passing to theatmosphere. An inlet check valve or one way valve on the inlet sidemight easily be added to the open end 23 of the inlet tube 22. On theoutlet side, a tee-connection with another one way check valve might beadded. In this manner, the patient will inhale through the nebulizer asdescribed herein. When the patient exhales, it will vent through theopposite side of the tee.

FIG. 2 illustrates an alternate embodiment 70 of the present invention.A housing 72 is normally positioned upright when the nebulizer is inuse. The housing has a substantially cylindrical chimney 74. At one endof the housing is an open bottom 76 and, at the opposite end, an opentop outlet 78.

An atmospheric air inlet tube 80 has a first end 82 which is open. Theair inlet tube 80 extends through the wall of the chimney 74 and extendsthrough and across the housing 72, traversing the diameter of thechimney 74.

From its entry point, the air inlet tube 80 extends to the opposite sideof the chimney 74 where a downward opening 86 is provided. The air inlettube is substantially perpendicular to the chimney of the housing 72.Ambient air entering the air intake tube will, thus, travel through andacross the housing and exit from the tube toward the open bottom 76 asindicated by arrows 88 and 90.

A bottom medication cup 92 is removably attached to and encloses theopen bottom 76 of the housing 72. In the embodiment shown, the openbottom 76 is internally threaded and the medication cup 92 is externallythreaded. When the bottom cup is attached, a closed chamber is formed,with the exception of the opening end 82 of the tube and the open topoutlet 78.

The bottom cup 92 has substantially cylindrical outer walls 94. Thebottom cup 92 has a conical portion 96 extending from a base 98 that isconcentric with the walls 94. At the concentric top of the conicalportion 96 is an orifice 100. Extending from the conical portion 96 andin communication with the orifice 100 is a nozzle holder 102. The nozzleholder would be connected to a source of pressurized air (not shown) sothat pressurized air would be delivered into the nebulizer 70. Receivedwithin the bottom medication cup 92 is a capillary cover 104 which nestson top of the conical portion of the bottom cup 92. The capillary cover104 has an opening 106 which is aligned with the orifice 100 of thebottom cup.

During operation of the nebulizer 70, a stream of pressurized airindicated by arrow 108 flows through the orifice of the bottom cup andcauses induction of the liquid medication 124 (illustrated by dashedlines) from the bottom cup through a space between the capillary coverand the conical portion. Accordingly, liquid droplets of medication willbe moved at high velocity through the orifice and into the housing 72.

A target frame 110 extends from the capillary cover and is above theopening 106 in the capillary cover. A target 112 is supported by theframe 110.

The target 112, thus, provides a target against which liquid dropletsand pressurized air will move at high velocity. The stream ofpressurized air and liquid droplets exiting from the opening 106 will,thus, be caused to impinge against the target 112. After striking thetarget 112, the mixture of liquid droplets and air will move upward andagainst the air inlet tube 80. It will be observed that the air inlettube 80 itself thus serves as a baffle mechanism for the liquidparticles.

Accurate skirts 114 extend radially outward from the air intake tube 80.The end of the skirts may touch and rest against the target frame 110.

Near the open bottom 76, the housing is an enlarged chamber 116 that isaxially aligned with the chimney and has a larger diameter than thechimney. Ambient air from the air intake tube will traverse the housingwithin the intake tube and will enter the enlarged chamber 116. The airwill then change direction and enter the chimney 74 as indicated by thearrows 118. Once inside the chimney, the air will pass around thehorizontal air intake tube 80 and mix with the liquid droplets andpressurized air. The fine mist produced by the liquid droplets andpressurized air impinging on the target 112 is mixed and swept alongwith the atmospheric air. The air flow is then directed upward throughthe interior of the chimney 74.

Finally, the saturated mist (the droplets which are surrounded by highrelative humidity) will exit the nebulizer 70 to be inhaled by thepatient and is not shown from the top outlet 78 as indicated by thearrow 120.

In the typical usage, a patient will inhale through outlet 78. However,the flow through the nebulizer 70 may be reversed. In that case, thepatient will inhale through inlet tube 80. Passage of the saturated mistthrough the circuitous route out of the tube 80 will further reduce thesize of the particles. During exhaling, to prevent any secretions fromthe patient from entering the medication cup, the interior of the inlettube may contain a raised shoulder 121 (seen in FIG. 2).

Returning to a consideration of the air intake tube 80, a longitudinalchamber 122 extends adjacent the chimney 74. The chamber 122 extendsradially from and is in communication with the air intake tube 80. Ifthe nebulizer 70 is accidentally tipped from the upright position in onedirection, any liquid medication will flow into the chamber 122. If thenebulizer is accidentally tipped from the upright position in theopposite direction, the liquid medication will flow into the enlargedchamber 116. The foregoing arrangement and design prevents liquidmedication from spilling out of the intake tube 80 or out of the chimneytop outlet 78.

FIG. 3 is a top view of the nebulizer 10 shown in FIG. 1. The traversalof the air inlet tube 22 across the housing 14 may be observed byviewing through the open top outlet 20. It will be appreciated that themixture of liquid droplets, pressurized air and atmospheric air mustpass around the air intake tube before passing up the chimney 16 and outof the open top outlet 20.

FIG. 4 is a side view of the nebulizer 10 shown in FIG. 1. Thelongitudinal chamber 60 is readily observable. If the nebulizer istipped from the upright position or turned upside down, the liquidmedication 16 in the bottom cup will flow into the longitudinal chamber.The medication will thus be prevented from spilling out of thenebulizer.

Whereas the present invention has been described in relation to thedrawings attached hereto, it should be understood that other and furthermodifications, apart from those shown or suggested herein, may be madewithin the spirit and scope of this invention.

What is claimed is:
 1. A nebulizer which comprises:(a) a bottom cup forstoring liquid medication therein, said bottom cup having an openingtherethrough to receive a source of pressurized air; (b) a substantiallycylindrical housing having an open bottom removably attachable to saidbottom cup, and an open top outlet; (c) an air inlet tube traversingsaid housing, said air inlet tube extending a cross the diameter of saidhousing perpendicular to said housing and terminating in an apertureadjacent said open bottom so that substantially all of the air enteringsaid inlet tube upon inhalation of a patient will pass across andtransversely to said housing before entering said housing adjacent saidopen bottom; and (d) a cover receivable within said bottom cup so thatliquid medication may be drawn from said bottom cup by induction andform droplets, whereby said air inlet tube of said housing acts as atarget for said pressurized air and said liquid droplets to impingethereon, thereby breaking said droplets into micron-size droplets.
 2. Anebulizer as set forth in claim 1 wherein said housing includes acylindrical chamber axially aligned and in communication with saidhousing having a diameter larger than said housing, so that air fromsaid air inlet tube will pass into said cylindrical chamber.
 3. Anebulizer as set forth in claim 1 wherein said bottom cup is threadablyreceived on said open bottom of said housing.
 4. A nebulizer as setforth in claim 1 wherein said air inlet tube has a protrusion extendingradially toward said open bottom and wherein said liquid droplets andsaid pressurized air will impinge on said protrusion, thereby breakingsaid liquid into micron-size droplets.
 5. A nebulizer as set forth inclaim 4 including a pair of opposed accurate skirts extending from saidair inlet tube, said accurate skirts surrounding said protrusion andspaced inwardly from said housing.
 6. A nebulizer as set forth in claim5 wherein said accurate skirts rest against said cover.
 7. A nebulizeras set forth in claim 1 including a spillage prevention and atomizationchamber in fluid communication with said inlet tube extendinglongitudinally along the exterior of said housing to retain liquidmedication in the event said nebulizer is tilted form a n uprightposition.
 8. A nebulizer as set forth in claim 1 wherein said bottom cuphas a conical portion extending from a base and said pressurized airopening is at a concentric top of said conical portion and wherein saidcover is received over said conical portion for delivery of liquidmedication by induction.
 9. A nebulizer as set forth in claim 1including removable check valve means in said housing near said open topoutlet to provide secondary baffling and restrict passage of largerparticles.
 10. A nebulizer as set forth in claim 1 wherein said airinlet tube includes an interior raised shoulder to prevent secretionsfrom passing to the bottom cup.